Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm...
[cascardo/linux.git] / drivers / nvdimm / pmem.c
index 4c079d5..b952538 100644 (file)
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/module.h>
+#include <linux/memory_hotplug.h>
 #include <linux/moduleparam.h>
+#include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/pmem.h>
 #include <linux/nd.h>
+#include "pfn.h"
 #include "nd.h"
 
 struct pmem_device {
        struct request_queue    *pmem_queue;
        struct gendisk          *pmem_disk;
+       struct nd_namespace_common *ndns;
 
        /* One contiguous memory region per device */
        phys_addr_t             phys_addr;
+       /* when non-zero this device is hosting a 'pfn' instance */
+       phys_addr_t             data_offset;
        void __pmem             *virt_addr;
        size_t                  size;
 };
@@ -44,7 +50,7 @@ static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
                        sector_t sector)
 {
        void *mem = kmap_atomic(page);
-       size_t pmem_off = sector << 9;
+       phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
        void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
 
        if (rw == READ) {
@@ -92,19 +98,26 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 }
 
 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
-                             void **kaddr, unsigned long *pfn, long size)
+                     void __pmem **kaddr, unsigned long *pfn)
 {
        struct pmem_device *pmem = bdev->bd_disk->private_data;
-       size_t offset = sector << 9;
-
-       if (!pmem)
-               return -ENODEV;
+       resource_size_t offset = sector * 512 + pmem->data_offset;
+       resource_size_t size;
+
+       if (pmem->data_offset) {
+               /*
+                * Limit the direct_access() size to what is covered by
+                * the memmap
+                */
+               size = (pmem->size - offset) & ~ND_PFN_MASK;
+       } else
+               size = pmem->size - offset;
 
        /* FIXME convert DAX to comprehend that this mapping has a lifetime */
-       *kaddr = (void __force *) pmem->virt_addr + offset;
+       *kaddr = pmem->virt_addr + offset;
        *pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
 
-       return pmem->size - offset;
+       return size;
 }
 
 static const struct block_device_operations pmem_fops = {
@@ -119,27 +132,33 @@ static struct pmem_device *pmem_alloc(struct device *dev,
 {
        struct pmem_device *pmem;
 
-       pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
+       pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
        if (!pmem)
                return ERR_PTR(-ENOMEM);
 
        pmem->phys_addr = res->start;
        pmem->size = resource_size(res);
-       if (!arch_has_pmem_api())
+       if (!arch_has_wmb_pmem())
                dev_warn(dev, "unable to guarantee persistence of writes\n");
 
-       if (!request_mem_region(pmem->phys_addr, pmem->size, dev_name(dev))) {
+       if (!devm_request_mem_region(dev, pmem->phys_addr, pmem->size,
+                       dev_name(dev))) {
                dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
                                &pmem->phys_addr, pmem->size);
-               kfree(pmem);
                return ERR_PTR(-EBUSY);
        }
 
-       pmem->virt_addr = memremap_pmem(pmem->phys_addr, pmem->size);
-       if (!pmem->virt_addr) {
-               release_mem_region(pmem->phys_addr, pmem->size);
-               kfree(pmem);
-               return ERR_PTR(-ENXIO);
+       if (pmem_should_map_pages(dev)) {
+               void *addr = devm_memremap_pages(dev, res);
+
+               if (IS_ERR(addr))
+                       return addr;
+               pmem->virt_addr = (void __pmem *) addr;
+       } else {
+               pmem->virt_addr = memremap_pmem(dev, pmem->phys_addr,
+                               pmem->size);
+               if (!pmem->virt_addr)
+                       return ERR_PTR(-ENXIO);
        }
 
        return pmem;
@@ -147,13 +166,16 @@ static struct pmem_device *pmem_alloc(struct device *dev,
 
 static void pmem_detach_disk(struct pmem_device *pmem)
 {
+       if (!pmem->pmem_disk)
+               return;
+
        del_gendisk(pmem->pmem_disk);
        put_disk(pmem->pmem_disk);
        blk_cleanup_queue(pmem->pmem_queue);
 }
 
-static int pmem_attach_disk(struct nd_namespace_common *ndns,
-               struct pmem_device *pmem)
+static int pmem_attach_disk(struct device *dev,
+               struct nd_namespace_common *ndns, struct pmem_device *pmem)
 {
        struct gendisk *disk;
 
@@ -162,6 +184,7 @@ static int pmem_attach_disk(struct nd_namespace_common *ndns,
                return -ENOMEM;
 
        blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
+       blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE);
        blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX);
        blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
        queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue);
@@ -179,8 +202,8 @@ static int pmem_attach_disk(struct nd_namespace_common *ndns,
        disk->queue             = pmem->pmem_queue;
        disk->flags             = GENHD_FL_EXT_DEVT;
        nvdimm_namespace_disk_name(ndns, disk->disk_name);
-       disk->driverfs_dev = &ndns->dev;
-       set_capacity(disk, pmem->size >> 9);
+       disk->driverfs_dev = dev;
+       set_capacity(disk, (pmem->size - pmem->data_offset) / 512);
        pmem->pmem_disk = disk;
 
        add_disk(disk);
@@ -209,11 +232,152 @@ static int pmem_rw_bytes(struct nd_namespace_common *ndns,
        return 0;
 }
 
-static void pmem_free(struct pmem_device *pmem)
+static int nd_pfn_init(struct nd_pfn *nd_pfn)
+{
+       struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
+       struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
+       struct nd_namespace_common *ndns = nd_pfn->ndns;
+       struct nd_region *nd_region;
+       unsigned long npfns;
+       phys_addr_t offset;
+       u64 checksum;
+       int rc;
+
+       if (!pfn_sb)
+               return -ENOMEM;
+
+       nd_pfn->pfn_sb = pfn_sb;
+       rc = nd_pfn_validate(nd_pfn);
+       if (rc == 0 || rc == -EBUSY)
+               return rc;
+
+       /* section alignment for simple hotplug */
+       if (nvdimm_namespace_capacity(ndns) < ND_PFN_ALIGN
+                       || pmem->phys_addr & ND_PFN_MASK)
+               return -ENODEV;
+
+       nd_region = to_nd_region(nd_pfn->dev.parent);
+       if (nd_region->ro) {
+               dev_info(&nd_pfn->dev,
+                               "%s is read-only, unable to init metadata\n",
+                               dev_name(&nd_region->dev));
+               goto err;
+       }
+
+       memset(pfn_sb, 0, sizeof(*pfn_sb));
+       npfns = (pmem->size - SZ_8K) / SZ_4K;
+       /*
+        * Note, we use 64 here for the standard size of struct page,
+        * debugging options may cause it to be larger in which case the
+        * implementation will limit the pfns advertised through
+        * ->direct_access() to those that are included in the memmap.
+        */
+       if (nd_pfn->mode == PFN_MODE_PMEM)
+               offset = ALIGN(SZ_8K + 64 * npfns, PMD_SIZE);
+       else if (nd_pfn->mode == PFN_MODE_RAM)
+               offset = SZ_8K;
+       else
+               goto err;
+
+       npfns = (pmem->size - offset) / SZ_4K;
+       pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
+       pfn_sb->dataoff = cpu_to_le64(offset);
+       pfn_sb->npfns = cpu_to_le64(npfns);
+       memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
+       memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
+       pfn_sb->version_major = cpu_to_le16(1);
+       checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
+       pfn_sb->checksum = cpu_to_le64(checksum);
+
+       rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
+       if (rc)
+               goto err;
+
+       return 0;
+ err:
+       nd_pfn->pfn_sb = NULL;
+       kfree(pfn_sb);
+       return -ENXIO;
+}
+
+static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
+{
+       struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
+       struct pmem_device *pmem;
+
+       /* free pmem disk */
+       pmem = dev_get_drvdata(&nd_pfn->dev);
+       pmem_detach_disk(pmem);
+
+       /* release nd_pfn resources */
+       kfree(nd_pfn->pfn_sb);
+       nd_pfn->pfn_sb = NULL;
+
+       return 0;
+}
+
+static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
 {
-       memunmap_pmem(pmem->virt_addr);
-       release_mem_region(pmem->phys_addr, pmem->size);
-       kfree(pmem);
+       struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+       struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
+       struct device *dev = &nd_pfn->dev;
+       struct vmem_altmap *altmap;
+       struct nd_region *nd_region;
+       struct nd_pfn_sb *pfn_sb;
+       struct pmem_device *pmem;
+       phys_addr_t offset;
+       int rc;
+
+       if (!nd_pfn->uuid || !nd_pfn->ndns)
+               return -ENODEV;
+
+       nd_region = to_nd_region(dev->parent);
+       rc = nd_pfn_init(nd_pfn);
+       if (rc)
+               return rc;
+
+       if (PAGE_SIZE != SZ_4K) {
+               dev_err(dev, "only supported on systems with 4K PAGE_SIZE\n");
+               return -ENXIO;
+       }
+       if (nsio->res.start & ND_PFN_MASK) {
+               dev_err(dev, "%s not memory hotplug section aligned\n",
+                               dev_name(&ndns->dev));
+               return -ENXIO;
+       }
+
+       pfn_sb = nd_pfn->pfn_sb;
+       offset = le64_to_cpu(pfn_sb->dataoff);
+       nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
+       if (nd_pfn->mode == PFN_MODE_RAM) {
+               if (offset != SZ_8K)
+                       return -EINVAL;
+               nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
+               altmap = NULL;
+       } else {
+               rc = -ENXIO;
+               goto err;
+       }
+
+       /* establish pfn range for lookup, and switch to direct map */
+       pmem = dev_get_drvdata(dev);
+       memunmap_pmem(dev, pmem->virt_addr);
+       pmem->virt_addr = (void __pmem *)devm_memremap_pages(dev, &nsio->res);
+       if (IS_ERR(pmem->virt_addr)) {
+               rc = PTR_ERR(pmem->virt_addr);
+               goto err;
+       }
+
+       /* attach pmem disk in "pfn-mode" */
+       pmem->data_offset = offset;
+       rc = pmem_attach_disk(dev, ndns, pmem);
+       if (rc)
+               goto err;
+
+       return rc;
+ err:
+       nvdimm_namespace_detach_pfn(ndns);
+       return rc;
 }
 
 static int nd_pmem_probe(struct device *dev)
@@ -222,7 +386,6 @@ static int nd_pmem_probe(struct device *dev)
        struct nd_namespace_common *ndns;
        struct nd_namespace_io *nsio;
        struct pmem_device *pmem;
-       int rc;
 
        ndns = nvdimm_namespace_common_probe(dev);
        if (IS_ERR(ndns))
@@ -233,18 +396,27 @@ static int nd_pmem_probe(struct device *dev)
        if (IS_ERR(pmem))
                return PTR_ERR(pmem);
 
+       pmem->ndns = ndns;
        dev_set_drvdata(dev, pmem);
        ndns->rw_bytes = pmem_rw_bytes;
+
        if (is_nd_btt(dev))
-               rc = nvdimm_namespace_attach_btt(ndns);
-       else if (nd_btt_probe(ndns, pmem) == 0) {
+               return nvdimm_namespace_attach_btt(ndns);
+
+       if (is_nd_pfn(dev))
+               return nvdimm_namespace_attach_pfn(ndns);
+
+       if (nd_btt_probe(ndns, pmem) == 0) {
                /* we'll come back as btt-pmem */
-               rc = -ENXIO;
-       } else
-               rc = pmem_attach_disk(ndns, pmem);
-       if (rc)
-               pmem_free(pmem);
-       return rc;
+               return -ENXIO;
+       }
+
+       if (nd_pfn_probe(ndns, pmem) == 0) {
+               /* we'll come back as pfn-pmem */
+               return -ENXIO;
+       }
+
+       return pmem_attach_disk(dev, ndns, pmem);
 }
 
 static int nd_pmem_remove(struct device *dev)
@@ -252,10 +424,11 @@ static int nd_pmem_remove(struct device *dev)
        struct pmem_device *pmem = dev_get_drvdata(dev);
 
        if (is_nd_btt(dev))
-               nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
+               nvdimm_namespace_detach_btt(pmem->ndns);
+       else if (is_nd_pfn(dev))
+               nvdimm_namespace_detach_pfn(pmem->ndns);
        else
                pmem_detach_disk(pmem);
-       pmem_free(pmem);
 
        return 0;
 }